sha1: win32: fix compilation due to unknown type In commit bbf034ab9 (hash: move `git_hash_prov` into Win32 backend, 2019-02-22), the `git_hash_prov`'s structure name has been removed in favour of its typedef'ed name. But as we have no CI that compiles with the WinHTTPS hashing backend right now, it wasn't noticed that the implementation that uses this struct wasn't changed correctly. Fix the struct type to make it compile again.
diff --git a/src/hash/sha1/win32.c b/src/hash/sha1/win32.c
index 1b944e2..c736956 100644
--- a/src/hash/sha1/win32.c
+++ b/src/hash/sha1/win32.c
@@ -23,7 +23,7 @@
/* BCRYPT_HASH_REUSEABLE_FLAGS */
#define GIT_HASH_CNG_HASH_REUSABLE 0x00000020
-static struct git_hash_prov hash_prov = {0};
+static git_hash_prov hash_prov = {0};
/* Hash initialization */