Change visibility of alloc share/unshare functions to pub(crate)

This cl modifies the visibility of several alloc share/unshare
functions from pub to pub(crate). This is because these functions
are only used within the crate and do not need to be accessed
outside of it.

Test: m pvmfw_img
Test: atest rialto_test
Bug: 274441673
Change-Id: Ie0165d23d7d5b0a3885965d9574b6715dd32fc8c
diff --git a/vmbase/src/memory/util.rs b/vmbase/src/memory/util.rs
index 48d4c55..2b75414 100644
--- a/vmbase/src/memory/util.rs
+++ b/vmbase/src/memory/util.rs
@@ -88,7 +88,7 @@
 ///
 /// As we use identity mapping for everything, this is just a cast, but it's useful to use it to be
 /// explicit about where we are converting from virtual to physical address.
-pub fn virt_to_phys(vaddr: NonNull<u8>) -> usize {
+pub(crate) fn virt_to_phys(vaddr: NonNull<u8>) -> usize {
     vaddr.as_ptr() as _
 }
 
@@ -96,6 +96,6 @@
 /// physical address.
 ///
 /// Panics if `paddr` is 0.
-pub fn phys_to_virt(paddr: usize) -> NonNull<u8> {
+pub(crate) fn phys_to_virt(paddr: usize) -> NonNull<u8> {
     NonNull::new(paddr as _).unwrap()
 }