Remove superfluous include from zeroize.c

This brings zeroize.c and test_zeroize.gdb in sync with development.

The include was introduced in 3b0c43063 (#2710).
Reverts ff8ae1115 from the same pull request.

Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
diff --git a/tests/scripts/test_zeroize.gdb b/tests/scripts/test_zeroize.gdb
index ec6524b..c929c88 100644
--- a/tests/scripts/test_zeroize.gdb
+++ b/tests/scripts/test_zeroize.gdb
@@ -43,7 +43,7 @@
 set confirm off
 
 file ./programs/test/zeroize
-break zeroize.c:102
+break zeroize.c:100
 
 set args ./programs/test/zeroize.c
 run