NFC: Directly initialize the 's' variable.

As part of enabling -Wconditional-uninitialized, there are some false
positives. See https://bugs.llvm.org/show_bug.cgi?id=38856 for more info
about the limited flow analysis. To facilitate turning this flag on more
widely, we can just directly initialize these variables.

Bug: http://b/131390872
Test: Builds with -Wconditional-uninitialized.
Change-Id: Id6633a06478dfb0c51a1a3b0cabf4c4e5d57abaa