panfrost: Fix off-by-one in varying count assert

We want to assert that the number of varyings (the count) is at most the
the maximum count. This is <=, not <, with the assertion previously
failing for exactly the maximum.

Fixes: 2c2cf0ecfe ("panfrost: Streamline varying linking code")
Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13070>

src/gallium/drivers/panfrost/pan_cmdstream.c

@@ -2106,8 +2106,8 @@ panfrost_emit_varying_descs(
 
         /* Offsets within the general varying buffer, indexed by location */
         signed offsets[PIPE_MAX_ATTRIBS];
-        assert(producer_count < ARRAY_SIZE(offsets));
-        assert(consumer_count < ARRAY_SIZE(offsets));
+        assert(producer_count <= ARRAY_SIZE(offsets));
+        assert(consumer_count <= ARRAY_SIZE(offsets));
 
         /* Allocate enough descriptors for both shader stages */
         struct panfrost_ptr T =