cabinet: Declare a function static

[Andrew Talbot]

Changelog:
    cabinet: Declare a function static.

diff --git a/dlls/cabinet/cabinet.h b/dlls/cabinet/cabinet.h
index e786c1f..8b38f9b 100644
--- a/dlls/cabinet/cabinet.h
+++ b/dlls/cabinet/cabinet.h
@@ -656,6 +656,5 @@ typedef struct {
 /* from fdi.c */
 void QTMupdatemodel(struct QTMmodel *model, int sym);
 int make_decode_table(cab_ULONG nsyms, cab_ULONG nbits, const cab_UBYTE *length, cab_UWORD *table);
-cab_ULONG checksum(const cab_UBYTE *data, cab_UWORD bytes, cab_ULONG csum);
 
 #endif /* __WINE_CABINET_H */
diff --git a/dlls/cabinet/fdi.c b/dlls/cabinet/fdi.c
index 4923404..bb40dfc 100644
--- a/dlls/cabinet/fdi.c
+++ b/dlls/cabinet/fdi.c
@@ -293,7 +293,7 @@ int make_decode_table(cab_ULONG nsyms, cab_ULONG nbits, const cab_UBYTE *length,
 /*************************************************************************
  * checksum (internal)
  */
-cab_ULONG checksum(const cab_UBYTE *data, cab_UWORD bytes, cab_ULONG csum) {
+static cab_ULONG checksum(const cab_UBYTE *data, cab_UWORD bytes, cab_ULONG csum) {
   int len;
   cab_ULONG ul = 0;