Don't fall off the end of perl functions

This complies with the perlcritic policy
Subroutines::RequireFinalReturn, which is a severity 4 policy. Since we
only currently check at severity level 5, the policy is raised to that
level until we move to level 4 or lower, so that any new infringements
will be caught.

A small cosmetic piece of tidying of the pgperlcritic script is
included.

Mike Blackwell

Discussion: https://postgr.es/m/CAESHdJpfFm_9wQnQ3koY3c91FoRQsO-fh02za9R3OEMndOn84A@mail.gmail.com

src/tools/msvc/Mkvcbuild.pm

@@ -964,6 +964,7 @@ sub AddContrib
 
 	# Are there any output data files to build?
 	GenerateContribSqlFiles($n, $mf);
+	return;
 }
 
 sub GenerateContribSqlFiles
@@ -1010,6 +1011,7 @@ sub GenerateContribSqlFiles
 			}
 		}
 	}
+	return;
 }
 
 sub AdjustContribProj
@@ -1020,6 +1022,7 @@ sub AdjustContribProj
 		\@contrib_uselibpq,       \@contrib_uselibpgport,
 		\@contrib_uselibpgcommon, $contrib_extralibs,
 		$contrib_extrasource,     $contrib_extraincludes);
+	return;
 }
 
 sub AdjustFrontendProj
@@ -1030,6 +1033,7 @@ sub AdjustFrontendProj
 		\@frontend_uselibpq,       \@frontend_uselibpgport,
 		\@frontend_uselibpgcommon, $frontend_extralibs,
 		$frontend_extrasource,     $frontend_extraincludes);
+	return;
 }
 
 sub AdjustModule
@@ -1086,6 +1090,7 @@ sub AdjustModule
 			$proj->AddFile($i);
 		}
 	}
+	return;
 }
 
 END