Fix DoneIfEdited and DoneIfIdentical, which became conjoined twins

through some sort of freak copy-paste accident.

install/libinstall.pm

@@ -244,11 +244,8 @@ sub DoneIfEdited($) {
     my ($filename) = @_;
     if (!$filename) { PhaseFail("Bad filename passed to DoneIfEdited"); }
     open(FH,$filename) or return;
-    if (!-e $filename1 || !-e $filename2) {
-	return;
-    }
-    if (!ExecQuiet("cmp -s $filename1 $filename2")) {
-	PhaseSkip("Files $filename1 and $filename2 are identical");
+    if (grep /$MAGIC_STRING/, <FH>) {
+	PhaseSkip("File $filename has already been edited\n");
     }
 }
 
@@ -261,9 +258,11 @@ sub DoneIfIdentical($$) {
     if (!$filename1 || !$filename2) {
 	PhaseFail("Bad filename passed to DoneIfIdentical");
     }
-    open(FH,$filename1) or return;
-    if (grep /$MAGIC_STRING/, <FH>) {
-	PhaseSkip("File $filename has already been edited\n");
+    if (!-e $filename1 || !-e $filename2) {
+	return;
+    }
+    if (!ExecQuiet("cmp -s $filename1 $filename2")) {
+	PhaseSkip("Files $filename1 and $filename2 are identical");
     }
 }