parisc: turn csum_partial_copy_from_user() into csum_and_copy_from_user()

Already has the right semantics.  Incidentally. failing copy_from_user()
zeroes the tail of destination - no need to repeat that manually
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/parisc/include/asm/checksum.h

@@ -26,11 +26,12 @@ extern __wsum csum_partial(const void *, int, __wsum);
  */
 extern __wsum csum_partial_copy_nocheck(const void *, void *, int, __wsum);
 
+#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
 /*
  * this is a new version of the above that records errors it finds in *errp,
  * but continues and zeros the rest of the buffer.
  */
-extern __wsum csum_partial_copy_from_user(const void __user *src,
+extern __wsum csum_and_copy_from_user(const void __user *src,
 		void *dst, int len, __wsum sum, int *errp);
 
 /*

arch/parisc/lib/checksum.c

@@ -128,18 +128,12 @@ EXPORT_SYMBOL(csum_partial_copy_nocheck);
  * Copy from userspace and compute checksum.  If we catch an exception
  * then zero the rest of the buffer.
  */
-__wsum csum_partial_copy_from_user(const void __user *src,
+__wsum csum_and_copy_from_user(const void __user *src,
 					void *dst, int len,
 					__wsum sum, int *err_ptr)
 {
-	int missing;
-
-	missing = copy_from_user(dst, src, len);
-	if (missing) {
-		memset(dst + len - missing, 0, missing);
+	if (copy_from_user(dst, src, len))
 		*err_ptr = -EFAULT;
-	}
-		
 	return csum_partial(dst, len, sum);
 }
-EXPORT_SYMBOL(csum_partial_copy_from_user);
+EXPORT_SYMBOL(csum_and_copy_from_user);