storage_file: Declare virStorageSourceParseRBDColonString only in one header

The virStorageSourceParseRBDColonString() function is declared in
src/storage_file/storage_source.h and
src/storage_file/storage_source_backingstore.h but implemented
only in the .c that corresponds to the latter header file.
Therefore, drop declaration from storage_source.h as the function
is not implemented in its corresponding .c file.

Leftover from: 2d29a3a9d86b5f95a859888283e6caa98593b1d2
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/libxl/xen_xl.c

@@ -30,6 +30,7 @@
 #include "viralloc.h"
 #include "virstring.h"
 #include "storage_source.h"
+#include "storage_source_backingstore.h"
 #include "xen_xl.h"
 #include "libxl_capabilities.h"
 #include "libxl_conf.h"

src/storage_file/storage_source.h

@@ -66,11 +66,6 @@ int
 virStorageSourceNewFromBacking(virStorageSource *parent,
                                virStorageSource **backing);
 
-int
-virStorageSourceParseRBDColonString(const char *rbdstr,
-                                    virStorageSource *src)
-    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
-
 int
 virStorageSourceGetRelativeBackingPath(virStorageSource *top,
                                        virStorageSource *base,

src/storage_file/storage_source_backingstore.h

@@ -29,7 +29,8 @@ virStorageSourceParseBackingURI(virStorageSource *src,
 
 int
 virStorageSourceParseRBDColonString(const char *rbdstr,
-                                    virStorageSource *src);
+                                    virStorageSource *src)
+    ATTRIBUTE_NONNULL(1) ATTRIBUTE_NONNULL(2);
 
 int
 virStorageSourceParseBackingColon(virStorageSource *src,