cifs: fix silence compiler warnings showing up with gcc-4.7+

gcc-4.7.0 has started throwing these warnings when building cifs.ko.

CC [M]  fs/cifs/cifssmb.o
fs/cifs/cifssmb.c: In function ‘CIFSSMBSetCIFSACL’:
fs/cifs/cifssmb.c:3905:9: warning: array subscript is above array bounds [-Warray-bounds]
fs/cifs/cifssmb.c: In function ‘CIFSSMBSetFileInfo’:
fs/cifs/cifssmb.c:5711:8: warning: array subscript is above array bounds [-Warray-bounds]
fs/cifs/cifssmb.c: In function ‘CIFSSMBUnixSetFileInfo’:
fs/cifs/cifssmb.c:6001:25: warning: array subscript is above array bounds [-Warray-bounds]

This patch cleans up the code a bit by using the offsetof macro instead
of the funky "&pSMB->hdr.Protocol" construct.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
[Patch] arm: make return_address available for ARM_UNWIND

This fixes a warning saying:

    warning: #warning "TODO: return_address should use unwind tables"

And, this enables return_address using unwind information. If ARM_UNWIND is
selected, unwind_frame in unwind.c will be called in walk_stackframe.

Signed-off-by: sahara <keun-o.park at windriver.com>
fix most 'uninitialized' warnings during compilation