[libc] Fix math fuzzers (#101529)

Fix minor typos that accumulated while the math fuzzers were disabled.

libc/fuzzing/math/RemQuoDiff.h

@@ -34,13 +34,13 @@ void RemQuoDiff(RemQuoFunc<T> func1, RemQuoFunc<T> func2, const uint8_t *data,
   LIBC_NAMESPACE::fputil::FPBits<T> bits1(remainder1);
   LIBC_NAMESPACE::fputil::FPBits<T> bits2(remainder2);
 
-  if (bit1.is_nan()) {
-    if (!bit2.is_nan())
+  if (bits1.is_nan()) {
+    if (!bits2.is_nan())
       __builtin_trap();
     return;
   }
 
-  if (bit1.is_inf() != bit2.is_inf())
+  if (bits1.is_inf() != bits2.is_inf())
     __builtin_trap();
 
   // Compare only the 3 LS bits of the quotient.

libc/fuzzing/math/nextafter_differential_fuzz.cpp

@@ -17,6 +17,8 @@
 #include "src/math/nextafterf.h"
 #include "src/math/nextafterl.h"
 
+#include <math.h>
+
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
   TwoInputSingleOutputDiff<float, float>(&LIBC_NAMESPACE::nextafterf,
                                          &::nextafterf, data, size);