buildman: fix toolchain priority_list

'-elf' appears twice in the toolchain priority_list.
The second one is rudundant.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Simon Glass <sjg@chromium.org>
Acked-by: Simon Glass <sjg@chromium.org>

tools/buildman/toolchain.py

@@ -66,7 +66,7 @@ class Toolchain:
         Returns:
             Priority of toolchain, 0=highest, 20=lowest.
         """
-        priority_list = ['-elf', '-unknown-linux-gnu', '-linux', '-elf',
+        priority_list = ['-elf', '-unknown-linux-gnu', '-linux',
             '-none-linux-gnueabi', '-uclinux', '-none-eabi',
             '-gentoo-linux-gnu', '-linux-gnueabi', '-le-linux', '-uclinux']
         for prio in range(len(priority_list)):