ANDROID: fix up merge error in kasan_test.c

In commit 76645e0f ("kasan: test: add memcpy test that avoids
out-of-bounds write"), a merge error happened when bringing it into the
android14-5.15 tree.  Fix this up by removing the duplicate function.

Fixes: 76645e0f ("kasan: test: add memcpy test that avoids out-of-bounds write")
Change-Id: Iab3f399e4eb19f4e727b81244a8dc07b73805290
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>