[PATCH] include linux/stddef.h in swab.h uapi header

swab.h uses __always_inline without including the header where it is defined, this is exposed by musl based distributions where this macro is not defined by system C library headers unlike glibc where it is defined in sys/cdefs.h and that header gets pulled in indirectly via features.h -> sys/cdef

[PATCH] include linux/stddef.h in swab.h uapi header

swab.h uses __always_inline without including the header where it is defined, this is exposed by musl based distributions where this macro is not defined by system C library headers unlike glibc where it is defined in sys/cdefs.h and that header gets pulled in indirectly via features.h -> sys/cdef