cifs: merge CIFSSMBQueryEA with CIFSSMBQAllEAs

Add an "ea_name" parameter to CIFSSMBQAllEAs. When it's set make it
behave like CIFSSMBQueryEA does now. The current callers of
CIFSSMBQueryEA are converted to use CIFSSMBQAllEAs, and the old
CIFSSMBQueryEA function is removed.

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