cifs: fix compiler warning in CIFSSMBQAllEAs

The recent fix to the above function causes this compiler warning to pop
on some gcc versions:

  CC [M]  fs/cifs/cifssmb.o
fs/cifs/cifssmb.c: In function ‘CIFSSMBQAllEAs’:
fs/cifs/cifssmb.c:5708: warning: ‘ea_name_len’ may be used uninitialized in
this function

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>