travis: move git submodule update to run first

Currently, the astyle build is failing due to sourceforge.net downloads
failing.  Move the git submodule update before that since it's more
critical.

Change-Id: Ibbf32759eed0f557652de41e7bfec6e8a3058772
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-on: https://review.gerrithub.io/380532
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>

.travis.yml

@@ -17,6 +17,7 @@ addons:
       - libnuma-dev
 
 before_script:
+  - git submodule update --init
   - export MAKEFLAGS="-j$(nproc)"
   - if [ "$CC" = gcc ]; then
       wget https://downloads.sourceforge.net/project/astyle/astyle/astyle%203.0/astyle_3.0_linux.tar.gz;
@@ -26,7 +27,6 @@ before_script:
       export PATH=$PWD/bin:$PATH;
       popd;
     fi
-  - git submodule update --init
 
 script:
   - ./scripts/check_format.sh