intel/fs: Don't emit empty ELSE blocks.

While we can clean this up later, it's trivial to not generate the
stupid code in the first place, which saves some optimization work.
15 jobs for !574 with noelse in 12 minutes and 50 seconds (queued for 2 seconds)
latest detached
Status Job ID Name Coverage
  Containers Build
passed #222974
ubuntu

00:00:19

 
  Build+Test
passed #222975
autotools

00:12:28

passed #222977
meson-clang

00:09:49

passed #222983
meson-gallium-clover-llvm

00:07:15

passed #222984
meson-gallium-clover-llvm39

00:05:43

passed #222982
meson-gallium-drivers-other

00:08:48

passed #222981
meson-gallium-radeonsi

00:06:25

passed #222985
meson-gallium-st-other

00:07:08

passed #222976
meson-gallium-swr

00:09:23

passed #222980
meson-glvnd

00:05:37

passed #222979
meson-loader-classic-dri

00:05:53

passed #222978
meson-vulkan

00:03:40

passed #222987
scons-llvm

00:03:56

passed #222986
scons-nollvm

00:05:29

passed #222988
scons-swr

00:08:04