Makefile: use ginstall on Solaris

Regular install just doesn't seem to like man pages?!

Signed-off-by: Jens Axboe <axboe@kernel.dk>

Makefile

diff --git a/Makefile b/Makefile
index 1545505..a5322a9 100644
--- a/Makefile
+++ b/Makefile
@@ -167,7 +167,11 @@
 endif
 endif
 
-INSTALL = install
+ifeq ($(CONFIG_TARGET_OS), SunOS)
+	INSTALL = ginstall
+else
+	INSTALL = install
+endif
 prefix = /usr/local
 bindir = $(prefix)/bin