clarify message for non-obvious precedence (rust-lang#14043)

I ran across this message while writing code and thought it was quite
odd. I've simplified it and hopefully made it clearer for non-native
English speakers.

changelog: clarify message for non-obvious precedence

Author: Centri3

clippy_lints/src/precedence.rs

@@ -43,7 +43,7 @@ impl EarlyLintPass for Precedence {
                     cx,
                     PRECEDENCE,
                     expr.span,
-                    "operator precedence can trip the unwary",
+                    "operator precedence might not be obvious",
                     "consider parenthesizing your expression",
                     sugg,
                     appl,

tests/ui/precedence.stderr

@@ -1,4 +1,4 @@
-error: operator precedence can trip the unwary
+error: operator precedence might not be obvious
   --> tests/ui/precedence.rs:16:5
    |
 LL |     1 << 2 + 3;
@@ -7,61 +7,61 @@ LL |     1 << 2 + 3;
    = note: `-D clippy::precedence` implied by `-D warnings`
    = help: to override `-D warnings` add `#[allow(clippy::precedence)]`
 
-error: operator precedence can trip the unwary
+error: operator precedence might not be obvious
   --> tests/ui/precedence.rs:17:5
    |
 LL |     1 + 2 << 3;
    |     ^^^^^^^^^^ help: consider parenthesizing your expression: `(1 + 2) << 3`
 
-error: operator precedence can trip the unwary
+error: operator precedence might not be obvious
   --> tests/ui/precedence.rs:18:5
    |
 LL |     4 >> 1 + 1;
    |     ^^^^^^^^^^ help: consider parenthesizing your expression: `4 >> (1 + 1)`
 
-error: operator precedence can trip the unwary
+error: operator precedence might not be obvious
   --> tests/ui/precedence.rs:19:5
    |
 LL |     1 + 3 >> 2;
    |     ^^^^^^^^^^ help: consider parenthesizing your expression: `(1 + 3) >> 2`
 
-error: operator precedence can trip the unwary
+error: operator precedence might not be obvious
   --> tests/ui/precedence.rs:20:5
    |
 LL |     1 ^ 1 - 1;
    |     ^^^^^^^^^ help: consider parenthesizing your expression: `1 ^ (1 - 1)`
 
-error: operator precedence can trip the unwary
+error: operator precedence might not be obvious
   --> tests/ui/precedence.rs:21:5
    |
 LL |     3 | 2 - 1;
    |     ^^^^^^^^^ help: consider parenthesizing your expression: `3 | (2 - 1)`
 
-error: operator precedence can trip the unwary
+error: operator precedence might not be obvious
   --> tests/ui/precedence.rs:22:5
    |
 LL |     3 & 5 - 2;
    |     ^^^^^^^^^ help: consider parenthesizing your expression: `3 & (5 - 2)`
 
-error: operator precedence can trip the unwary
+error: operator precedence might not be obvious
   --> tests/ui/precedence.rs:23:5
    |
 LL |     0x0F00 & 0x00F0 << 4;
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider parenthesizing your expression: `0x0F00 & (0x00F0 << 4)`
 
-error: operator precedence can trip the unwary
+error: operator precedence might not be obvious
   --> tests/ui/precedence.rs:24:5
    |
 LL |     0x0F00 & 0xF000 >> 4;
    |     ^^^^^^^^^^^^^^^^^^^^ help: consider parenthesizing your expression: `0x0F00 & (0xF000 >> 4)`
 
-error: operator precedence can trip the unwary
+error: operator precedence might not be obvious
   --> tests/ui/precedence.rs:25:5
    |
 LL |     0x0F00 << 1 ^ 3;
    |     ^^^^^^^^^^^^^^^ help: consider parenthesizing your expression: `(0x0F00 << 1) ^ 3`
 
-error: operator precedence can trip the unwary
+error: operator precedence might not be obvious
   --> tests/ui/precedence.rs:26:5
    |
 LL |     0x0F00 << 1 | 2;