Revert "travis: try to run clang analyzer upon build time"

This reverts commit 4fa38bb62e.

Apparently scan-build isn't installed by default, therefore
something like the following would be needed:

 sudo add-apt-repository "deb http://ppa.launchpad.net/ubuntu-toolchain-r/test/ubuntu precise main"
 sudo add-apt-repository "deb http://llvm.org/apt/precise/ llvm-toolchain-precise-${CLANG_VERSION} main"
 wget -q -O - http://llvm.org/apt/llvm-snapshot.gpg.key | sudo apt-key add -
 sudo apt-get update -qq
 sudo apt-get install -y -q clang-${CLANG_VERSION}

.travis.yml

@@ -5,5 +5,4 @@ compiler:
 env:
   - DEBUG=
   - DEBUG=debug
-  - SCANBUILD=scan-build
-script: $SCANBUILD make $DEBUG
+script: make $DEBUG