tools/mpirun: include errno.h

With some configuration options (e.g., --with-threads=argobots), no
header includes "errno.h", causing a compile error because of undefined
errno.  errno.h should be included explicitly.

Signed-off-by: Shintaro Iwasaki <siwasaki@anl.gov>

Author: shintaro-iwasaki

ompi/tools/mpirun/main.c

@@ -10,6 +10,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
+#include <errno.h>
 #if HAVE_SYS_STAT_H
 #    include <sys/stat.h>
 #endif /* HAVE_SYS_STAT_H */