ANDROID: KVM: arm64: Fix error handling in pKVM FF-A proxy

__ffa_host_{un}share_ranges() returns the number of {un}shared pages,
and not 0 upon success, so make sure to check for that in the error path
of ffa_host_{un}share_ranges().

Bug: 236751556
Signed-off-by: Quentin Perret <qperret@google.com>
Change-Id: Ie122e394f1bc4ce79fcbb24d2a5c58cd53b3c146

arch/arm64/kvm/hyp/nvhe/ffa.c

diff --git a/arch/arm64/kvm/hyp/nvhe/ffa.c b/arch/arm64/kvm/hyp/nvhe/ffa.c
index 1fd6c6e..3bb1efc 100644
--- a/arch/arm64/kvm/hyp/nvhe/ffa.c
+++ b/arch/arm64/kvm/hyp/nvhe/ffa.c
@@ -324,7 +324,7 @@ static int ffa_host_share_ranges(struct ffa_mem_region_addr_range *ranges,
 	int ret = 0;
 
 	if (nshared != nranges) {
-		WARN_ON(__ffa_host_unshare_ranges(ranges, nshared));
+		WARN_ON(__ffa_host_unshare_ranges(ranges, nshared) != nshared);
 		ret = FFA_RET_DENIED;
 	}
 
@@ -338,7 +338,7 @@ static int ffa_host_unshare_ranges(struct ffa_mem_region_addr_range *ranges,
 	int ret = 0;
 
 	if (nunshared != nranges) {
-		WARN_ON(__ffa_host_share_ranges(ranges, nunshared));
+		WARN_ON(__ffa_host_share_ranges(ranges, nunshared) != nunshared);
 		ret = FFA_RET_DENIED;
 	}