fix: freebsd build support (#1659)

- Avoid hard-coding the path for bash - this typically is installed as
  /usr/local/bin/bash

- Allow for the fact that FreeBSD's rlimit uses signed integers

Almost all of the test suite passes with three test failures that I
haven't tried to debug yet.

Signed-off-by: Doug Rabson <dfr@rabson.org>

pkg/api/controller.go

@@ -75,7 +75,7 @@ func DumpRuntimeParams(log log.Logger) {
 
 	err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rLimit)
 	if err == nil {
-		evt = evt.Uint64("max. open files", rLimit.Cur)
+		evt = evt.Uint64("max. open files", uint64(rLimit.Cur)) //nolint: unconvert // required for *BSD
 	}
 
 	if content, err := os.ReadFile("/proc/sys/net/core/somaxconn"); err == nil {