[POWERPC] Fix uninitialized variable bug in copy_{to|from}_user

Calls to copy_to_user() or copy_from_user() can fail when copying N
bytes, where N is a constant less than 8, but not 1, 2, 4, or 8,
because 'ret' is not initialized and is only set if the size is 1,
2, 4 or 8, but is tested after the switch statement for any constant
size <= 8. This fixes it by initializing 'ret' to 1, causing the
code to fall through to the __copy_tofrom_user call for sizes other
than 1, 2, 4 or 8.

Signed-off-by: Dave Scidmore <[e-mail]>
Signed-off-by: Nate Case <[e-mail]>
Signed-off-by: Paul Mackerras <[e-mail]>

include/asm-powerpc/uaccess.h

···
 		const void __user *from, unsigned long n)
 {
 	if (__builtin_constant_p(n) && (n <= 8)) {
-		unsigned long ret;
+		unsigned long ret = 1;
 
 		switch (n) {
 		case 1:
···
 		const void *from, unsigned long n)
 {
 	if (__builtin_constant_p(n) && (n <= 8)) {
-		unsigned long ret;
+		unsigned long ret = 1;
 
 		switch (n) {
 		case 1: