Update the function comment for FindProgHeaderForMapping. (#601)
Added text to specify that it can return a nil program header in some cases.
diff --git a/internal/elfexec/elfexec.go b/internal/elfexec/elfexec.go
index b60357d..3b3c6ee 100644
--- a/internal/elfexec/elfexec.go
+++ b/internal/elfexec/elfexec.go
@@ -286,7 +286,8 @@
// FindProgHeaderForMapping returns the loadable program segment header that is
// fully contained in the runtime mapping with file offset pgoff and memory size
-// memsz, or an error if the segment cannot be determined.
+// memsz, or an error if the segment cannot be determined. The function returns
+// a nil program header and no error if the ELF binary has no loadable segments.
func FindProgHeaderForMapping(f *elf.File, pgoff, memsz uint64) (*elf.ProgHeader, error) {
var headers []*elf.ProgHeader
loadables := 0
