Fix warnings trivial warnings.

Fix warnings about:
 . Unused variables
 . format mismatch in printf/scanf format string and arguments
 . Missing parenthesis around assignment as truth values
 . Clang warnings anout unknown GCC pragma

lib/libc/gen/minix/times.c

@@ -8,8 +8,7 @@
 __weak_alias(times, _times)
 #endif
 
-clock_t times(buf)
-struct tms *buf;
+clock_t times(struct tms *buf)
 {
   message m;
 

lib/libc/gen/minix/uname.c

@@ -20,8 +20,7 @@ __weak_alias(uname, _uname)
 		return -1; \
 	name->string[sizeof(name->string)-1]= 0;
 
-int uname(name)
-struct utsname *name;
+int uname(struct utsname *name)
 {
 	int hf, n, err;
 	char *nl;

lib/libc/gen/minix/wait.c

@@ -8,8 +8,7 @@
 __weak_alias(wait, _wait)
 #endif
 
-pid_t wait(status)
-int * status;
+pid_t wait(int * status)
 {
   message m;
 

lib/libc/gen/minix/waitpid.c

@@ -8,10 +8,7 @@
 __weak_alias(waitpid, _waitpid)
 #endif
 
-pid_t waitpid(pid, status, options)
-pid_t pid;
-int *status;
-int options;
+pid_t waitpid(pid_t pid, int *status, int options)
 {
   message m;