init/host_init_verifier: Fix a compiler warning

Fix the following compiler warning:

//system/core/init:host_init_verifier clang++ host_init_verifier.cp
system/core/init/host_init_verifier.cpp:112:9: warning: ISO C++ requires field designators to be specified in declaration order; field 'pw_shell' will be initialized after field 'pw_uid' [-Wreorder-init-list]
        .pw_uid = 0,
        ^~~~~~~~~~~
system/core/init/host_init_verifier.cpp:111:21: note: previous initialization for field 'pw_shell' is here
        .pw_shell = static_shell,
                    ^~~~~~~~~~~~

Change-Id: I930c668d7fb1d12ebe9307b1549776da71a9a95a
Signed-off-by: Bart Van Assche <bvanassche@google.com>