jobs: Handle string-based job descriptors

When looking for a job using a string descriptor, e.g.

	fg %man

the relevant loop in src/jobs.c only ever exits to the err label. With
this patch, when the end condition is reached, we check whether a job
was found, and if so, set things up to exit correctly via gotit.
Multiple matches are already caught using the test in the match block.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

src/jobs.c

@@ -714,9 +714,7 @@ check:
 	}
 	found = 0;
-	while (1) {
-		if (!jp)
-			goto err;
+	while (jp) {
 		if (match(jp->ps[0].cmd, p)) {
 			if (found)
 				goto err;
@@ -726,6 +724,10 @@ check:
 		jp = jp->prev_job;
 	}
+	if (!found)
+		goto err;
+	jp = found;
+
 gotit:
 #if JOBS
 	err_msg = "job %s not created under job control";