Minor cleanup in Makefile.am

Split long lines where adding license info to dist archive.

Remove extra colon from target line.

Reviewed-by: Chris Dunlop <chris@onthe.net.au>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ryan Moeller <ryan@ixsystems.com>
Closes openzfs#9189

Makefile.am

@@ -25,11 +25,16 @@ EXTRA_DIST += META AUTHORS COPYRIGHT LICENSE NEWS NOTICE README.md
 EXTRA_DIST += CODE_OF_CONDUCT.md
 
 # Include all the extra licensing information for modules
-EXTRA_DIST += module/icp/algs/skein/THIRDPARTYLICENSE module/icp/algs/skein/THIRDPARTYLICENSE.descrip
-EXTRA_DIST += module/icp/asm-x86_64/aes/THIRDPARTYLICENSE.gladman module/icp/asm-x86_64/aes/THIRDPARTYLICENSE.gladman.descrip
-EXTRA_DIST += module/icp/asm-x86_64/aes/THIRDPARTYLICENSE.openssl module/icp/asm-x86_64/aes/THIRDPARTYLICENSE.openssl.descrip
-EXTRA_DIST += module/spl/THIRDPARTYLICENSE.gplv2 module/spl/THIRDPARTYLICENSE.gplv2.descrip
-EXTRA_DIST += module/zfs/THIRDPARTYLICENSE.cityhash module/zfs/THIRDPARTYLICENSE.cityhash.descrip
+EXTRA_DIST += module/icp/algs/skein/THIRDPARTYLICENSE
+EXTRA_DIST += module/icp/algs/skein/THIRDPARTYLICENSE.descrip
+EXTRA_DIST += module/icp/asm-x86_64/aes/THIRDPARTYLICENSE.gladman
+EXTRA_DIST += module/icp/asm-x86_64/aes/THIRDPARTYLICENSE.gladman.descrip
+EXTRA_DIST += module/icp/asm-x86_64/aes/THIRDPARTYLICENSE.openssl
+EXTRA_DIST += module/icp/asm-x86_64/aes/THIRDPARTYLICENSE.openssl.descrip
+EXTRA_DIST += module/spl/THIRDPARTYLICENSE.gplv2
+EXTRA_DIST += module/spl/THIRDPARTYLICENSE.gplv2.descrip
+EXTRA_DIST += module/zfs/THIRDPARTYLICENSE.cityhash
+EXTRA_DIST += module/zfs/THIRDPARTYLICENSE.cityhash.descrip
 
 @CODE_COVERAGE_RULES@
 
@@ -39,7 +44,7 @@ gitrev:
 
 BUILT_SOURCES = gitrev
 
-distclean-local::
+distclean-local:
 	-$(RM) -R autom4te*.cache
 	-find . \( -name SCCS -o -name BitKeeper -o -name .svn -o -name CVS \
 		-o -name .pc -o -name .hg -o -name .git \) -prune -o \