rebase: update go-ceph to v0.5.0

as go-ceph is 0.5.0 is released updating
the dependency to latest release.
more info about release at
https://github.com/ceph/go-ceph/releases/tag/v0.5.0

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/github.com/ceph/go-ceph/internal/cutil/splitbuf.go

@@ -0,0 +1,49 @@
+package cutil
+
+import "C"
+
+import (
+	"bytes"
+)
+
+// SplitBuffer splits a byte-slice buffer, typically returned from C code,
+// into a slice of strings.
+// The contents of the buffer are assumed to be null-byte separated.
+// If the buffer contains a sequence of null-bytes it will assume that the
+// "space" between the bytes are meant to be empty strings.
+func SplitBuffer(b []byte) []string {
+	return splitBufStrings(b, true)
+}
+
+// SplitSparseBuffer splits a byte-slice buffer, typically returned from C code,
+// into a slice of strings.
+// The contents of the buffer are assumed to be null-byte separated.
+// This function assumes that buffer to be "sparse" such that only non-null-byte
+// strings will be returned, and no "empty" strings exist if null-bytes
+// are found adjacent to each other.
+func SplitSparseBuffer(b []byte) []string {
+	return splitBufStrings(b, false)
+}
+
+// If keepEmpty is true, empty substrings will be returned, by default they are
+// excluded from the results.
+// This is almost certainly a suboptimal implementation, especially for
+// keepEmpty=true case. Optimizing the functions is a job for another day.
+func splitBufStrings(b []byte, keepEmpty bool) []string {
+	values := make([]string, 0)
+	// the final null byte should be the terminating null in C
+	// we never want to preserve the empty string after it
+	if len(b) > 0 && b[len(b)-1] == 0 {
+		b = b[:len(b)-1]
+	}
+	if len(b) == 0 {
+		return values
+	}
+	for _, s := range bytes.Split(b, []byte{0}) {
+		if !keepEmpty && len(s) == 0 {
+			continue
+		}
+		values = append(values, string(s))
+	}
+	return values
+}