GNU Make manual [1] clearly forbids a tab at the beginning of the
conditional directive line:
"Extra spaces are allowed and ignored at the beginning of the
conditional directive line, but a tab is not allowed."
This will not work for the next release of GNU Make, hence commit
82175d1f94 ("kbuild: Replace tabs with spaces when followed by
conditionals") replaced the inappropriate tabs with 8 spaces.
However, the 8-space indentation cannot be visually distinguished.
Linus suggested 2-4 spaces for those nested if-statements. [2]
This commit redoes the replacement with 4 spaces.
[1]: https://www.gnu.org/software/make/manual/make.html#Conditional-Syntax
[2]: https://lore.kernel.org/all/CAHk-=whJKZNZWsa-VNDKafS_VfY4a5dAjG-r8BZgWk_a-xSepw@mail.gmail.com/
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>