Add use strict and use warnings to perl callgrind scripts

This way we can simply use #! /usr/bin/env perl and don't need env -S
and perl -w flags which might confuse some packaging utilities.

callgrind/callgrind_annotate.in

@@ -1,4 +1,4 @@
-#! /usr/bin/env -S perl -w
+#! /usr/bin/env perl
 ##--------------------------------------------------------------------##
 ##--- The cache simulation framework: instrumentation, recording   ---##
 ##--- and results printing.                                        ---##
@@ -59,6 +59,7 @@
 #    commifying (halves the number of commify calls)            1.68s --> 1.47s
 
 use strict;
+use warnings;
 
 #----------------------------------------------------------------------------
 # Overview: the running example in the comments is for:

callgrind/callgrind_control.in

@@ -1,4 +1,4 @@
-#! /usr/bin/env -S perl -w
+#! /usr/bin/env perl
 ##--------------------------------------------------------------------##
 ##--- Control supervision of applications run with callgrind       ---##
 ##---                                            callgrind_control ---##
@@ -21,6 +21,10 @@
 #
 #  You should have received a copy of the GNU General Public License
 #  along with this program; if not, see <http://www.gnu.org/licenses/>.
+
+use strict;
+use warnings;
+
 use File::Basename;
 
 # vgdb_exe will be set to a vgdb found 'near' the callgrind_control file