cifsd: fix boolreturn.cocci warnings

fs/cifsd/smb2pdu.c:8098:8-9: WARNING: return of 0/1 in function
'smb2_is_sign_req' with return type bool

 Return statements in functions returning bool should use  true/false
instead of 1/0.
Generated by: scripts/coccinelle/misc/boolreturn.cocci
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: kernel test robot <lkp@intel.com>
Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifsd/smb2pdu.c

@@ -7713,7 +7713,7 @@ bool smb2_is_sign_req(struct ksmbd_work *work, unsigned int command)
 	    command != SMB2_OPLOCK_BREAK_HE)
 		return true;
 
-	return 0;
+	return false;
 }
 
 /**