6l: fix documentation of -L flag

R=rsc, iant2, iant
CC=golang-dev
https://golang.org/cl/3802044

src/cmd/5l/doc.go

@@ -20,8 +20,8 @@ Original options are listed in the link above.
 
 Options new in this version:
 
--L dir1,dir2,..
-	Search for libraries (package files) in the comma-separated list of directories.
+-L dir1 -L dir2
+	Search for libraries (package files) in dir1, dir2, etc.
 	The default is the single location $GOROOT/pkg/$GOOS_arm.
 -r dir1:dir2:...
 	Set the dynamic linker search path when using ELF.

src/cmd/6l/doc.go

@@ -32,8 +32,8 @@ Options new in this version:
 	Write Apple Mach-O binaries (default when $GOOS is darwin)
 -H7
 	Write Linux ELF binaries (default when $GOOS is linux)
--L dir1,dir2,..
-	Search for libraries (package files) in the comma-separated list of directories.
+-L dir1 -L dir2
+	Search for libraries (package files) in dir1, dir2, etc.
 	The default is the single location $GOROOT/pkg/$GOOS_amd64.
 -r dir1:dir2:...
 	Set the dynamic linker search path when using ELF.

src/cmd/8l/doc.go

@@ -29,8 +29,8 @@ Options new in this version:
 	Write Apple Mach-O binaries (default when $GOOS is darwin)
 -H7
 	Write Linux ELF binaries (default when $GOOS is linux)
--L dir1,dir2,..
-	Search for libraries (package files) in the comma-separated list of directories.
+-L dir1 -L dir2
+	Search for libraries (package files) in dir1, dir2, etc.
 	The default is the single location $GOROOT/pkg/$GOOS_386.
 -r dir1:dir2:...
 	Set the dynamic linker search path when using ELF.