Fix 2 occurrences of if-begin-to-cond

Using `cond` instead of `if` here makes `begin` unnecessary

Author: resyntax-ci[bot]

typed-racket-lib/typed-racket/typecheck/tc-expr-unit.rkt

@@ -317,9 +317,11 @@
               (attribute opt.value))
             (opt-convert fun-type required-pos optional-pos optional-supplied?)]
            [_ #f]))
-       (if conv-type
-           (begin (tc-expr/check/type #'fun conv-type) (fix-results expected))
-           (tc-expr/check form #f))]
+       (cond
+         [conv-type
+          (tc-expr/check/type #'fun conv-type)
+          (fix-results expected)]
+         [else (tc-expr/check form #f)])]
       [(~and _:kw-lambda^
              (let-values ([(f) fun])
                (let-values _

typed-racket-test/external/tr-random-testing.rkt

@@ -337,11 +337,11 @@
           )))
   (or both-failed?
       (and (not racket-failed?)
-           (if (same-result? racket-result racketbc-result)
-               #t
-               (begin (printf "not same as bc: racketcs: ~s racketbc: ~s\n"
-                              racket-result racketbc-result)
-                      #f)))))
+           (cond
+             [(same-result? racket-result racketbc-result) #t]
+             [else
+              (printf "not same as bc: racketcs: ~s racketbc: ~s\n" racket-result racketbc-result)
+              #f]))))
 
 (define num-exceptions 0)