crypto: sha256_ssse3 - fix stack corruption with SSSE3 and AVX implementations

The _XFER stack element size was set too small, 8 bytes, when it needs to be
16 bytes. As _XFER is the last stack element used by these implementations,
the 16 byte stores with 'movdqa' corrupt the stack where the value of register
%r12 is temporarily stored. As these implementations align the stack pointer
to 16 bytes, this corruption did not happen every time.

Patch corrects this issue.
Reported-by: NJulian Wollrath <jwollrath@web.de>
Signed-off-by: NJussi Kivilinna <jussi.kivilinna@iki.fi>
Tested-by: NJulian Wollrath <jwollrath@web.de>
Acked-by: NTim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

arch/x86/crypto/sha256-avx-asm.S

@@ -118,7 +118,7 @@ y2 = %r15d
 
 _INP_END_SIZE = 8
 _INP_SIZE = 8
-_XFER_SIZE = 8
+_XFER_SIZE = 16
 _XMM_SAVE_SIZE = 0
 
 _INP_END = 0

arch/x86/crypto/sha256-ssse3-asm.S

@@ -111,7 +111,7 @@ y2 = %r15d
 
 _INP_END_SIZE = 8
 _INP_SIZE = 8
-_XFER_SIZE = 8
+_XFER_SIZE = 16
 _XMM_SAVE_SIZE = 0
 
 _INP_END = 0