Fix a reference inside Makefile

Author: ermingol23

Makefile

@@ -3,7 +3,7 @@ SOURCES=diff-hl.el
 SOURCES+=diff-hl-amend.el
 SOURCES+=diff-hl-dired.el
 SOURCES+=diff-hl-flydiff.el
-SOURCES+=diff-hl-inline-popup.el
+SOURCES+=diff-hl-show-hunk-inline.el
 SOURCES+=diff-hl-margin.el
 SOURCES+=diff-hl-show-hunk-posframe.el
 SOURCES+=diff-hl-show-hunk.el