markup_oops.pl: minor fixes

1. Fix a little format issue.
2. Check the return of "Getopt::Long::GetOptions". Output usage and
exit if it get error.
3. Change $ARGV[$#ARGV] to $ARGV[0].
4. Change the code which get $modulefile from modinfo. Replace the
pipeline with `modinfo -F filename $module`.
4. Change usage from "Specify the module directory name" to "Specify the
module filename".

Signed-off-by: Hui Zhu <[e-mail]>
Signed-off-by: Michal Marek <[e-mail]>

scripts/markup_oops.pl

···
 # Get options
 Getopt::Long::GetOptions(
 	'cross-compile|c=s'	=> \$cross_compile,
-	'module|m=s'	=> \$modulefile,
+	'module|m=s'		=> \$modulefile,
 	'help|h'		=> \&usage,
-);
-my $vmlinux_name = $ARGV[$#ARGV];
+) || usage ();
+my $vmlinux_name = $ARGV[0];
 if (!defined($vmlinux_name)) {
 	my $kerver = `uname -r`;
 	chomp($kerver);
···
 # if it's a module, we need to find the .ko file and calculate a load offset
 if ($module ne "") {
 	if ($modulefile eq "") {
-		my $modulefile = `modinfo $module | grep '^filename:' | awk '{ print \$2 }'`;
+		$modulefile = `modinfo -F filename $module`;
 		chomp($modulefile);
 	}
 	$filename = $modulefile;
···
 
 OPTION:
   -c, --cross-compile CROSS_COMPILE	Specify the prefix used for toolchain.
-  -m, --module MODULE_DIRNAME		Specify the module directory name.
+  -m, --module MODULE_DIRNAME		Specify the module filename.
   -h, --help				Help.
 EOT
 	exit;