Documentation: quotes around TARGET_CC command.

When ccache is enabled, TARGET_CC is "ccache gcc". Without quotes,
when assigning CC=$(TARGET_CC), only "ccache" gets assigned to CC.

Signed-off-by: Shawn J. Goff <shawn7400@gmail.com>
Acked-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

docs/buildroot.html

@@ -905,7 +905,7 @@ source "package/libfoo/Config.in"
 <span style="color: #000000">10:</span><span style="color: #009900"> LIBFOO_DEPENDENCIES</span> = host-libaaa libbbb
 <span style="color: #000000">11:</span>
 <span style="color: #000000">12:</span> define LIBFOO_BUILD_CMDS
-<span style="color: #000000">13:</span> 	<span style="color: #009900">$(MAKE)</span> CC=<span style="color: #009900">$(TARGET_CC)</span> LD=<span style="color: #009900">$(TARGET_LD)</span> -C <span style="color: #009900">$(@D)</span> all
+<span style="color: #000000">13:</span> 	<span style="color: #009900">$(MAKE)</span> CC=<span style="color: #009900">"$(TARGET_CC)"</span> LD=<span style="color: #009900">"$(TARGET_LD)"</span> -C <span style="color: #009900">$(@D)</span> all
 <span style="color: #000000">14:</span> endef
 <span style="color: #000000">15:</span>
 <span style="color: #000000">16:</span> define LIBFOO_INSTALL_STAGING_CMDS

docs/manual/adding-packages-gentargets.txt

@@ -24,7 +24,7 @@ system is based on hand-written Makefiles or shell scripts.
 10: LIBFOO_DEPENDENCIES = host-libaaa libbbb
 11:
 12: define LIBFOO_BUILD_CMDS
-13: 	$(MAKE) CC=$(TARGET_CC) LD=$(TARGET_LD) -C $(@D) all
+13: 	$(MAKE) CC="$(TARGET_CC)" LD="$(TARGET_LD)" -C $(@D) all
 14: endef
 15:
 16: define LIBFOO_INSTALL_STAGING_CMDS