xf86drm: Fix indentation

libdrm uses spaces for indentation. Fix the two inconsistent lines in
this file.

Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/xf86drm.c b/xf86drm.c
index 7d7df18..b8b2cfe 100644
--- a/xf86drm.c
+++ b/xf86drm.c
@@ -2908,7 +2908,7 @@
 
     return -EINVAL;
 #elif defined(__OpenBSD__)
-	return DRM_BUS_PCI;
+    return DRM_BUS_PCI;
 #else
 #warning "Missing implementation of drmParseSubsystemType"
     return -EINVAL;
@@ -3419,7 +3419,7 @@
     closedir(sysdir);
     free(local_devices);
     if (*device == NULL)
-	return -ENODEV;
+        return -ENODEV;
     return 0;
 
 free_devices: