builddeb: put the dbg files into the correct directory

commit 2d087139 upstream.

Since the conversion of objtree to use relative pathnames (commit
7e1c0477, "kbuild: Use relative path for $(objtree)"), the debug
info files have been ending up in /debian/dbgtmp/ in the regular
linux-image package instead of the debug files package. Fix up the
paths so that the debug files end up in the -dbg package.

This is based on a similar patch by Darrick.
Reported-and-tested-by: "Darrick J. Wong" <darrick.wong@oracle.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

scripts/package/builddeb

@@ -152,18 +152,16 @@ if grep -q '^CONFIG_MODULES=y' $KCONFIG_CONFIG ; then
 		rmdir "$tmpdir/lib/modules/$version"
 	fi
 	if [ -n "$BUILD_DEBUG" ] ; then
-		(
-			cd $tmpdir
-			for module in $(find lib/modules/ -name *.ko); do
-				mkdir -p $(dirname $dbg_dir/usr/lib/debug/$module)
-				# only keep debug symbols in the debug file
-				$OBJCOPY --only-keep-debug $module $dbg_dir/usr/lib/debug/$module
-				# strip original module from debug symbols
-				$OBJCOPY --strip-debug $module
-				# then add a link to those
-				$OBJCOPY --add-gnu-debuglink=$dbg_dir/usr/lib/debug/$module $module
-			done
-		)
+		for module in $(find $tmpdir/lib/modules/ -name *.ko -printf '%P\n'); do
+			module=lib/modules/$module
+			mkdir -p $(dirname $dbg_dir/usr/lib/debug/$module)
+			# only keep debug symbols in the debug file
+			$OBJCOPY --only-keep-debug $tmpdir/$module $dbg_dir/usr/lib/debug/$module
+			# strip original module from debug symbols
+			$OBJCOPY --strip-debug $tmpdir/$module
+			# then add a link to those
+			$OBJCOPY --add-gnu-debuglink=$dbg_dir/usr/lib/debug/$module $tmpdir/$module
+		done
 	fi
 fi