cifs: Use ULL suffix for 64-bit constant

On 32-bit (e.g. with m68k-linux-gnu-gcc-4.1):

    fs/cifs/inode.c: In function ‘simple_hashstr’:
    fs/cifs/inode.c:713: warning: integer constant is too large for ‘long’ type

Fixes: 7ea884c ("smb3: Fix root directory when server returns inode number of zero")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>

fs/cifs/inode.c

@@ -710,7 +710,7 @@ cifs_get_file_info(struct file *filp)
 /* Simple function to return a 64 bit hash of string.  Rarely called */
 static __u64 simple_hashstr(const char *str)
 {
-	const __u64 hash_mult =  1125899906842597L; /* a big enough prime */
+	const __u64 hash_mult =  1125899906842597ULL; /* a big enough prime */
 	__u64 hash = 0;
 
 	while (*str)