.travis.yml: Remove the unneeded '&' for ls20xx buildman

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/.travis.yml b/.travis.yml
index a3e7451..3aaed93 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -200,7 +200,7 @@
         - BUILDMAN="freescale&aarch64&ls108"
     - name: "buildman NXP AArch64 LS20xx"
       env:
-        - BUILDMAN="freescale&aarch64&&ls20"
+        - BUILDMAN="freescale&aarch64&ls20"
     - name: "buildman NXP AArch64 LX216x"
       env:
         - BUILDMAN="freescale&aarch64&lx216"