tools/elfutils: remove no-op copy of tdestroy()

A false tdestroy() function was added in order to make elfutils build on
macOS again. A previous commit added declarations for a real version of
tdestroy() into gnulib, which is already imported, as well as the
preprocessor flags and the triggers for the Makefile.am conditional in
order to include the source to be built.

Tested-by: Georgi Valkov <gvalkov@gmail.com> # MacOS
Signed-off-by: Michael Pratt <mcpratt@pm.me>
Signed-off-by: Tony Ambardar <itugrok@yahoo.com>

tools/elfutils/patches/100-portability.patch

@@ -344,20 +344,6 @@
 +{
 +  return ppc_check_object_attribute(ebl, vendor, tag, value, tag_name, value_name);
 +}
---- a/lib/libeu.h
-+++ b/lib/libeu.h
-@@ -45,4 +45,11 @@ extern char *xasprintf(const char *fmt,
- extern uint32_t crc32 (uint32_t crc, unsigned char *buf, size_t len);
- extern int crc32_file (int fd, uint32_t *resp);
- 
-+#ifdef __APPLE__
-+static inline void tdestroy(void *root __attribute__ ((unused)),
-+			    void (*freekey)(void *) __attribute__ ((unused)))
-+{
-+}
-+#endif
-+
- #endif
 --- a/libdwfl/libdwflP.h
 +++ b/libdwfl/libdwflP.h
 @@ -31,6 +31,8 @@