Merge branch 'jc/varargs-attributes'

Varargs functions that are unannotated as printf-like or execl-like have been annotated as such. * jc/varargs-attributes: __attribute__: add a few missing format attributes __attribute__: mark some functions with LAST_ARG_MUST_BE_NULL __attribute__: remove redundant attribute declaration for git_die_config() __attribute__: trace2_region_enter_printf() is like "printf"