build: Install bash completions below DESTDIR

Honour the DESTDIR variable when installing the bash completion script.

Fixes #566.

Signed-off-by: James O. D. Hunt <james.o.hunt@intel.com>

Makefile

@@ -76,9 +76,6 @@ PKGLIBDIR := $(LOCALSTATEDIR)/lib/$(CCDIR)
 PKGRUNDIR := $(LOCALSTATEDIR)/run/$(CCDIR)
 PKGLIBEXECDIR := $(LIBEXECDIR)/$(CCDIR)
 
-BASH_COMPLETIONS := data/completions/bash/cc-runtime
-BASH_COMPLETIONSDIR := $(SHAREDIR)/bash-completion/completions
-
 KERNELPATH := $(PKGDATADIR)/vmlinuz.container
 IMAGEPATH := $(PKGDATADIR)/clear-containers.img
 
@@ -129,8 +126,13 @@ DESTTARGET := $(abspath $(DESTBINDIR)/$(TARGET))
 DESTCONFDIR := $(DESTDIR)/$(SYSCONFDIR)/$(CCDIR)
 DESTCONFIG := $(abspath $(DESTCONFDIR)/$(CONFIG_FILE))
 
+DESTSHAREDIR := $(DESTDIR)/$(SHAREDIR)
+
 PAUSEDESTDIR := $(abspath $(DESTDIR)/$(PAUSEROOTPATH)/$(PAUSEBINRELPATH))
 
+BASH_COMPLETIONS := data/completions/bash/cc-runtime
+BASH_COMPLETIONSDIR := $(DESTSHAREDIR)/bash-completion/completions
+
 # list of variables the user may wish to override
 USER_VARS += BASH_COMPLETIONSDIR
 USER_VARS += BINDIR