header guards: clean up some stragglers

Some headers had been missed during the initial header guard
standardization.

Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Laurent Vivier <lvivier@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20210610135937.94375-2-cohuck@redhat.com>
diff --git a/lib/pci.h b/lib/pci.h
index 689f03c..e201711 100644
--- a/lib/pci.h
+++ b/lib/pci.h
@@ -1,5 +1,5 @@
-#ifndef PCI_H
-#define PCI_H
+#ifndef _PCI_H_
+#define _PCI_H_
 /*
  * API for scanning a PCI bus for a given device, as well to access
  * BAR registers.
@@ -102,4 +102,4 @@
 
 #define  PCI_HEADER_TYPE_MASK		0x7f
 
-#endif /* PCI_H */
+#endif /* _PCI_H_ */