Fix inconsistent function call in Submodule.

submodule.go

@@ -11,6 +11,15 @@ import (
 	"unsafe"
 )
 
+// SubmoduleUpdateOptions
+type SubmoduleUpdateOptions struct {
+	*CheckoutOpts
+	*RemoteCallbacks
+	Version               uint64
+	CloneCheckoutStrategy CheckoutStrategy
+	Signature             *Signature
+}
+
 // Submodule
 type Submodule struct {
 	ptr *C.git_submodule
@@ -226,8 +235,8 @@ func (sub *Submodule) SetIgnore(ignore SubmoduleIgnore) SubmoduleIgnore {
 	return SubmoduleIgnore(o)
 }
 
-func (sub *Submodule) Update() SubmoduleUpdate {
-	o := C.git_submodule_update(sub.ptr)
+func (sub *Submodule) UpdateStrategy() SubmoduleUpdate {
+	o := C.git_submodule_update_strategy(sub.ptr)
 	return SubmoduleUpdate(o)
 }
 

vendor/libgit2

@@ -1 +1 @@
-Subproject commit 55d9c29aa0c69cdd766c5100fc012d8e0b486e23
+Subproject commit 007f3ff6fa68a95feee4e70f825a49ea0ec9cb2d