git: Readd function in spull alias

This reverts commit 54d716510b ("git: Drop function in `spull`").

I apparently oversaw the use of arguments passed to `git pull`. This
makes the function necessary.

.config/git/config

@@ -7,7 +7,7 @@
 	fixes = log -1 --pretty=fixes
 	root = rev-parse --show-toplevel
 	signoff = "!\"${XDG_CONFIG_HOME:-$HOME/.config}/zsh/autoload/git/git-signoff\""
-	spull = "!git pull \"$@\" && git submodule sync --recursive && git submodule update --init --recursive;"
+	spull = "!__git_spull() { git pull \"$@\" && git submodule sync --recursive && git submodule update --init --recursive; }; __git_spull"
 	track = "!\"${XDG_CONFIG_HOME:-$HOME/.config}/zsh/autoload/git/git-track\""
 [blame]
 	date = short