[CIFS] cifs: remove pointless lock and unlock of GlobalMid_Lock in header_assemble

We lock GlobalMid_Lock in header_assemble and then immediately unlock it
again without doing anything. Not sure what this was intended to do, but
remove it.
Signed-off-by: NJeff Layton <jlayton@redhat.com>
Signed-off-by: NSteve French <sfrench@us.ibm.com>

fs/cifs/misc.c

@@ -311,8 +311,6 @@ header_assemble(struct smb_hdr *buffer, char smb_command /* command */ ,
 	buffer->Flags2 = SMBFLG2_KNOWS_LONG_NAMES;
 	buffer->Pid = cpu_to_le16((__u16)current->tgid);
 	buffer->PidHigh = cpu_to_le16((__u16)(current->tgid >> 16));
-	spin_lock(&GlobalMid_Lock);
-	spin_unlock(&GlobalMid_Lock);
 	if (treeCon) {
 		buffer->Tid = treeCon->tid;
 		if (treeCon->ses) {