[PATCH 2/2] Makefile: let header dependency checker override COMPUTE_HEADER_DEPENDENCIES

This way, if you have “COMPUTE_HEADER_DEPENDENCIES = YesPlease” in your
config.mak, you can still “make CHECK_HEADER_DEPENDENCIES=Yes” to check
the makefile after a successful build.

This change does not affect the result of the command
“make CHECK_HEADER_DEPENDENCIES=Yes COMPUTE_HEADER_DEPENDENCIES=Yes”.
That will still die with an error message:

	cannot compute header dependencies outside a normal build

The message is appropriate because still true.

Signed-off-by: Jonathan Nieder <redacted>
---
 Makefile |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/Makefile b/Makefile
index 567b859..0025b98 100644
--- a/Makefile
+++ b/Makefile

@@ -1063,6 +1063,7 @@ endif
 -include config.mak
 
 ifdef CHECK_HEADER_DEPENDENCIES
+COMPUTE_HEADER_DEPENDENCIES =
 USE_COMPUTED_HEADER_DEPENDENCIES =
 endif
 

-- 
1.7.1