Change salloc job_allocate error message header

from "Failed to allocate resources" to
"Job submit/allocate failed"

src/salloc/salloc.c

@@ -344,7 +344,7 @@ int main(int argc, char *argv[])
 			error("Unable to allocate resources: %m");
 			error_exit = immediate_exit;
 		} else {
-			error("Failed to allocate resources: %m");
+			error("Job submit/allocate failed: %m");
 		}
 		slurm_allocation_msg_thr_destroy(msg_thr);
 		exit(error_exit);

testsuite/expect/test15.10

@@ -54,7 +54,7 @@ for {set inx 1} {$inx < 4} {set inx [expr $inx * 2]} {
 			send "exit\r"
 			exp_continue
 		}
-		-re "Failed to allocate.*" {
+		-re "allocate failed" {
 			send_user "\nThis error is not unexpected, no worries\n"
 			set tasks_get $tasks_set
 		}