Rename ProcResult stdout and stderr fields

stdout and stderr are macros in musl, which causes build failures
when they are used as field names.  Rename the fields to stdout_str
and stderr_str.

Test: builds
Merged-In: I04770d2d6e82ca8393308ab12a304838a80f0ae5
Change-Id: I04770d2d6e82ca8393308ab12a304838a80f0ae5
5 files changed