hush: fix NOMMU hangs in pseudo_exec_argv. Add forgotted setting

 of signal mask. Reuse same help string in all shells.

function                                             old     new   delta
builtin_exit                                          49      47      -2
pseudo_exec_argv                                     149     145      -4
builtin_help                                          74      63     -11
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-17)             Total: -17 bytes
   text    data     bss     dec     hex filename
 825379     476    7616  833471   cb7bf busybox_old
 825341     476    7616  833433   cb799 busybox_unstripped

1 files changed, 3 insertions, 3 deletions

diff --git a/shell/msh.c b/shell/msh.c
index 5f8c90ef6..da1dc3576 100644
--- a/shell/msh.c
+++ b/shell/msh.c
@@ -35,7 +35,6 @@
 # include <assert.h>
 # define bb_dev_null "/dev/null"
 # define DEFAULT_SHELL "/proc/self/exe"
-# define CONFIG_BUSYBOX_EXEC_PATH "/proc/self/exe"
 # define bb_banner "busybox standalone"
 # define ENABLE_FEATURE_SH_STANDALONE 0
 # define bb_msg_memory_exhausted "memory exhausted"
@@ -3176,8 +3175,9 @@ static int dohelp(struct op *t UNUSED_PARAM, char **args UNUSED_PARAM)
         int col;
         const struct builtincmd *x;
 
-        puts("\nBuilt-in commands:\n"
-             "-------------------");
+        printf("\n"
+                "Built-in commands:\n"
+                "------------------\n");
 
         col = 0;
         x = builtincmds;