Fuzzer: The return value of malloc is void *, it does not need to be forced to change the type

Signed-off-by: Li zeming <zeming@nfschina.com>

tests/thirdparty/Fuzzer/standalone/StandaloneFuzzTargetMain.c

@@ -31,7 +31,7 @@ int main(int argc, char **argv) {
     fseek(f, 0, SEEK_END);
     size_t len = ftell(f);
     fseek(f, 0, SEEK_SET);
-    unsigned char *buf = (unsigned char*)malloc(len);
+    unsigned char *buf = malloc(len);
     size_t n_read = fread(buf, 1, len, f);
     assert(n_read == len);
     LLVMFuzzerTestOneInput(buf, len);