eina: Lets allocate space for the terminating \0 as well

Off-by-1 in string copy, found by klocwork

Signed-off-by: Daniel Willmann <d.willmann@samsung.com>

src/lib/eina/eina_prefix.c

@@ -505,7 +505,7 @@ eina_prefix_new(const char *argv0, void *symbol, const char *envprefix,
      }
    if (magicsharefile)
      {
-        magic = alloca(strlen(magicsharefile));
+        magic = alloca(strlen(magicsharefile) + 1);
         strcpy(magic, magicsharefile);
         _path_sep_fix(magic);
      }