Use "#!/usr/bin/env perl" as shebang line.

scripts/config.pl

@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
 #
 # This file is part of mbed TLS (https://tls.mbed.org)
 #

scripts/generate_errors.pl

@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
 
 # Generate error.c
 #

scripts/generate_features.pl

@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
 #
 
 use strict;

scripts/generate_visualc_files.pl

@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
 
 # Generate files for MS Visual Studio:
 # - for VS6: main project (library) file, individual app files, workspace

scripts/massif_max.pl

@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
 
 # Parse a massif.out.xxx file and output peak total memory usage
 

scripts/rename.pl

@@ -1,4 +1,4 @@
-#!/usr/bin/perl
+#!/usr/bin/env perl
 #
 # This file is part of mbed TLS (https://tls.mbed.org)
 #