staging/lustre: Declare lprocfs_write_frac_u64_helper argument as __user

The buffer that lprocfs_write_frac_u64_helper is working on is
presumed to be a userspace one, so it's not suitable for use
on kernel buffers.
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/lustre/lustre/include/lprocfs_status.h

@@ -608,7 +608,7 @@ int lprocfs_write_helper(const char __user *buffer, unsigned long count,
 			 int *val);
 int lprocfs_write_u64_helper(const char __user *buffer,
 			     unsigned long count, __u64 *val);
-int lprocfs_write_frac_u64_helper(const char *buffer,
+int lprocfs_write_frac_u64_helper(const char __user *buffer,
 				  unsigned long count,
 				  __u64 *val, int mult);
 char *lprocfs_find_named_value(const char *buffer, const char *name,

drivers/staging/lustre/lustre/obdclass/lprocfs_status.c

@@ -1319,8 +1319,8 @@ int lprocfs_write_u64_helper(const char __user *buffer, unsigned long count,
 }
 EXPORT_SYMBOL(lprocfs_write_u64_helper);
 
-int lprocfs_write_frac_u64_helper(const char *buffer, unsigned long count,
-			      __u64 *val, int mult)
+int lprocfs_write_frac_u64_helper(const char __user *buffer,
+				  unsigned long count, __u64 *val, int mult)
 {
 	char kernbuf[22], *end, *pbuf;
 	__u64 whole, frac = 0, units;