[Buildroot] [git commit branch/next] Makefile: fix performance regression caused by the umask handling

[Thomas Petazzoni]

commit: http://git.buildroot.net/buildroot/commit/?id=1e9f60471622ec48f4df9ffe09e6cbca3a3ca6aa
branch: http://git.buildroot.net/buildroot/commit/?id=refs/heads/next

Commit bee5745c introduced an extra level of 'make' when the umask is
different from 0022. However, when several targets were specified on
the command line, a new make instance would be called for each target.
This introduces a huge performance overhead when many targets are
specified on the command line.

To fix this, use the same approach as used in the mkmakefile script:
an addition target on which the MAKECMDGOALS depend, so that this
target is run only once.

Note that the mkmakefile script contains a special exception for
Makefile, because the Makefile in the output directory is generated.
Since the top-level Makefile is not generated, this exception is not
needed here.

While we're at it, also fix the whitespace in the UMASK assignment.

Signed-off-by: Guido Martínez <guido at vanguardiasur.com.ar>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
[yann.morin.1998 at free.fr: aggregate patches from Arnout and Guido]
Signed-off-by: Yann E. MORIN <yann.morin.1998 at free.fr>
Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout at mind.be>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
---
 Makefile |   12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/Makefile b/Makefile
index 168d62a..8b9c5d9 100644
--- a/Makefile
+++ b/Makefile
@@ -25,15 +25,15 @@
 #--------------------------------------------------------------
 
 # Trick for always running with a fixed umask
-UMASK=0022
+UMASK = 0022
 ifneq ($(shell umask),$(UMASK))
-.PHONY: all $(MAKECMDGOALS)
+.PHONY: _all $(MAKECMDGOALS)
 
-all:
-	@umask $(UMASK) && $(MAKE) --no-print-directory
+$(MAKECMDGOALS): _all
+	@:
 
-$(MAKECMDGOALS):
-	@umask $(UMASK) && $(MAKE) --no-print-directory $@
+_all:
+	@umask $(UMASK) && $(MAKE) --no-print-directory $(MAKECMDGOALS)
 
 else # umask