mpatch: switch alignment of wrapped line from tab to spaces with clang-format
I may be a weird person for liking this style, but our C style is
historically nominally the Linux Kernel style, and when you configure
clang-format to be kernel-ish, this is what you get. If we want to
change it, we can do so by tweaking the formatter rules in the future.
Differential Revision: https://phab.mercurial-scm.org/D1132