drm/gpu: Remove dead checks on wbinvd_on_all_cpus()'s return value

Remove the checks and associated pr_err() on wbinvd_on_all_cpus() failure,
as the helper has unconditionally returned 0/success since commit

  caa7593 ("smp: Remove smp_call_function() and on_each_cpu() return values").

Signed-off-by: Sean Christopherson <[email protected]>
Signed-off-by: Borislav Petkov (AMD) <[email protected]>
Link: https://lore.kernel.org/[email protected]

Author: sean-jc

drivers/gpu/drm/drm_cache.c

@@ -93,8 +93,7 @@ drm_clflush_pages(struct page *pages[], unsigned long num_pages)
 		return;
 	}
 
-	if (wbinvd_on_all_cpus())
-		pr_err("Timed out waiting for cache flush\n");
+	wbinvd_on_all_cpus();
 
 #elif defined(__powerpc__)
 	unsigned long i;
@@ -139,8 +138,7 @@ drm_clflush_sg(struct sg_table *st)
 		return;
 	}
 
-	if (wbinvd_on_all_cpus())
-		pr_err("Timed out waiting for cache flush\n");
+	wbinvd_on_all_cpus();
 #else
 	WARN_ONCE(1, "Architecture has no drm_cache.c support\n");
 #endif
@@ -172,8 +170,7 @@ drm_clflush_virt_range(void *addr, unsigned long length)
 		return;
 	}
 
-	if (wbinvd_on_all_cpus())
-		pr_err("Timed out waiting for cache flush\n");
+	wbinvd_on_all_cpus();
 #else
 	WARN_ONCE(1, "Architecture has no drm_cache.c support\n");
 #endif