patch 9.1.0561: netbeans: variable used un-initialized (Coverity)

Problem:  netbeans: variable used un-initialized (Coverity)
          (after v9.1.0557)
Solution: properly initialize exarg_T struct for use with netbeans

The actual exarg.cmdidx doesn't really matter, but let's use something,
that is not affected by the recent changes (going through the buffer
list) and use CMD_USER.

closes: #15211

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/netbeans.c b/src/netbeans.c
index 3b68869..781caa8 100644
--- a/src/netbeans.c
+++ b/src/netbeans.c
@@ -1689,8 +1689,10 @@
 	    if (streq((char *)args, "T") && buf->bufp != curbuf)
 	    {
 		exarg_T exarg;
+		CLEAR_FIELD(exarg);
 		exarg.cmd = (char_u *)"goto";
 		exarg.forceit = FALSE;
+		exarg.cmdidx = CMD_USER;
 		dosetvisible = TRUE;
 		goto_buffer(&exarg, DOBUF_FIRST, FORWARD, buf->bufp->b_fnum);
 		do_update = 1;