linux-user: Fix typo in comment

Signed-off-by: NLei Li <lilei@linux.vnet.ibm.com>
Reviewed-by: NStefan Weil <sw@weilnetz.de>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>

linux-user/syscall.c

@@ -8236,7 +8236,7 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
 #ifdef TARGET_NR_madvise
     case TARGET_NR_madvise:
         /* A straight passthrough may not be safe because qemu sometimes
-           turns private flie-backed mappings into anonymous mappings.
+           turns private file-backed mappings into anonymous mappings.
            This will break MADV_DONTNEED.
            This is a hint, so ignoring and returning success is ok.  */
         ret = get_errno(0);