libxenguest: drop now unused le32_to_cpup() from lz4 decompression

While gcc doesn't warn about this because of it being static inline,
clang does, causing the build to fail there because of -Werror.

Fixes: d8099d94df ("libxenguest: add get_unaligned_le32()")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>

tools/libs/guest/xg_dom_decompress_lz4.c

@@ -22,11 +22,6 @@ static inline uint_fast16_t le16_to_cpup(const unsigned char *buf)
     return buf[0] | (buf[1] << 8);
 }
 
-static inline uint_fast32_t le32_to_cpup(const unsigned char *buf)
-{
-    return le16_to_cpup(buf) | ((uint32_t)le16_to_cpup(buf + 2) << 16);
-}
-
 #include "../../xen/include/xen/lz4.h"
 #include "../../xen/common/decompress.h"