fix(test): correct operator precedence

bitshift shift has lower precedence than division, meaning in
MemoryUsageExceededError.__init__ we end up trying to bitshift a float,
which is nonsense (as the expression in the f-string gets interpreted as
(threshold / 1) << 20, and the result of all divisions in python is a
float). Add some parenthesis.

We cannot just write this as `threshold >> 20`, as we care about the
fractional part.

Fixes: 7d1549f ("tests: fix MMIO gaps in memory monitor tool")
Signed-off-by: Patrick Roy <[email protected]>

Author: roypat

tests/host_tools/memory.py

@@ -17,8 +17,8 @@ class MemoryUsageExceededError(Exception):
     def __init__(self, usage, threshold, *args):
         """Compose the error message containing the memory consumption."""
         super().__init__(
-            f"Memory usage ({usage / 1 << 20:.2f} MiB) exceeded maximum threshold "
-            f"({threshold / 1 << 20} MiB)",
+            f"Memory usage ({usage / (1 << 20):.2f} MiB) exceeded maximum threshold "
+            f"({threshold / (1 << 20)} MiB)",
             *args,
         )