get_maintainer: improve patch recognition

There are mode change and rename only patches that are unrecognized
by the get_maintainer.pl script.

Recognize them.

Link: http://lkml.kernel.org/r/bf63101a908d0ff51948164aa60e672368066186.1526949367.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Reported-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/get_maintainer.pl

@@ -542,7 +542,18 @@ foreach my $file (@ARGV) {
 
 	while (<$patch>) {
 	    my $patch_line = $_;
-	    if (m/^\+\+\+\s+(\S+)/ or m/^---\s+(\S+)/) {
+	    if (m/^ mode change [0-7]+ => [0-7]+ (\S+)\s*$/) {
+		my $filename = $1;
+		push(@files, $filename);
+	    } elsif (m/^rename (?:from|to) (\S+)\s*$/) {
+		my $filename = $1;
+		push(@files, $filename);
+	    } elsif (m/^diff --git a\/(\S+) b\/(\S+)\s*$/) {
+		my $filename1 = $1;
+		my $filename2 = $2;
+		push(@files, $filename1);
+		push(@files, $filename2);
+	    } elsif (m/^\+\+\+\s+(\S+)/ or m/^---\s+(\S+)/) {
 		my $filename = $1;
 		$filename =~ s@^[^/]*/@@;
 		$filename =~ s@\n@@;